Apparatus for counting revolutions of predetermined time range



pt- 16, 1969 L. J. ARP 3,467,821

APPARATUS FOR COUNTING REVOLUTIONS OF PREDETERMINED TIME RANGE Filed Oct. 13, 1965 COUNT/El? a United States Patent 3 467,821 APPARATUS FOR COIJNTIN G REVOLUTIONS OF PREDETERMINED TIME RANGE Leon J. Arp, 1221 Marston, Ames, Iowa 50010 Filed Oct. 13, 1965, Ser. No. 495,650 Int. Cl. G06f 7/38 US. Cl. 235-92 3 Claims ABSTRACT OF THE DISCLOSURE The invention relates to an apparatus for counting only the revolutions of a rotating member which occur within a predetermined time range, which apparatus comprises a normally open relay in a normally open electric circuit, which relay is operable in response to each rotation of the member due to a magnetic device mounted on the member passing thereby to temporarily close the circuit, a counter which is actuated only when the circuit is closed, a normally open switch in the circuit which is movable to a closed condition wherein the circuit is closed, and a timer device operable by the closing of the relay to place the switch in its closed position for a predetermined period of time, the timer device also operable to automatically place the switch in its inoperativeopen condition.

This invention relates to a revolution counter or speed sensing apparatus in general, and more particularly to an apparatus for counting the revolutions of a rotating member, which revolutions occur within a given time range.

Although appropriately useable in other readily envisaged areas, the invention is particularly applicable for use with concrete hauling vehicles where the concrete is constantly being mixed in the large rotating drum mounted on the vehicle. Each state, and possibly other jurisdictions, have certain specifications as to the state and condition of the cement, and which are based at least in part on the exact number of revolutions of a vehicles drum, with each revolution occurring within a given time range, usually of seconds.

An example would be x number of revolutions, with each revolution taking not less than 2.57 seconds and not more than 8.57 seconds. Thus, if a revolution took 2.56 seconds, or 8.58 seconds, it should not be counted. The instant invention is predicated on providing such a counting apparatus, and maintaining such accuracy in counting by the most practical, economical, and efiicient structure.

It is an object of this invention to provide a novel and useable apparatus for counting only the revolutions of a rotating member which occur within a predetermined time range.

It is another object of this invention to provide a revolution counting apparatus having a counting mechanism operable only when each revolution occurs within a given time range, and wherein the apparatus discards revolutions both less than and more than said time range.

Yet another object of this invention is to provide a revolution counting apparatus utilizing a magnetic relay combination with the rotating member for actuating a timing circuit for recording each rotation within a given time range.

Still another object of this invention is to provide a revolution counting apparatus which counts only those revolutions occurring within a given time range, and which visibly indicates each revolution not counted.

It is another object of this invention to provide a preferred electromechanical arrangement and a modification thereof, both of which attain the above designated objectives and which are simple in structure and circuitry, economical, rugged and effective in operation, and easy to maintain.

3,467,821 Patented Sept. 16, 1969 These objects, and other features and advantages of this invention will become readily apparent upon reference to the following description when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic circuit diagram of a preferred embodiment of the revolution counting apparatus of this invention; and

FIG. 2 is a schematic circuit diagram of a modified embodiment of the invention.

Referring now to the drawing, and particularly to FIG. 1, a rotating member is indicated at 10 as the member the revolutions of which occur within a certain period of time are desired to be recorded. The member 10 could be the drum, for example, of a vehicular cement mixer, or of course any rotating member operably connected therewith. A north-south pole magnet 11 is fastened to the member 10 for operating a normally open reed-type relay 12 responsive to the magnetic lines of force of the magnet 11. Thus, each instant the magnet rotates past the relay 12, the latter is temporarily closed, opening again when the magnetic force is removed.

The relay 12 is interposed between a positive DC. voltage source at 13, and a pair of circuit legs each leading to the negative DC. voltage sources at 14 and 16. The closed circuit leg includes a resistance 17 in series with an electromagnet 18, and with which a diode 19 is in parallel. A capacitor 21 is connected between the negative potential source and a junction 22 intermediate the resistance 17 and the electromagnet 18 for a purpose hereinafter described.

The other circuit leg is normally open and includes another electromagnet 23, in parallel with which is a diode 24, both connected by line 26 to a bar 27. Engageable with the bar 27 is a pivotally mounted switch 28, one portion of which is always electrically connected to the negative voltage source 14.

The embodiment of FIG. 1 includes further a conven tional escapement timer mechanism indicated generally at 29, and operable when energized to move, according to a predetermined time schedule, a timer arm 31 in a clockwise direction, said movement aided by the provision of a biasing spring 32.

The normal position of the switch 28 is shown in full lines, and is open relative to the bar 27. Upon engagement of the switch 28 with the arm 31, the switch 28 is then moved to the dotted line, closed position with the bar 27. In this latter position or condition of the switch 28, upon a momentary closing of the relay 12 the circuit through the electromagnet 18 is closed such as to energize a counter mechanism 33 to record the revolution of the member 10.

Full operation of the FIG. 1 embodiment is as follows. Upon rotation of the rotating member 10 in a direction as indicated by the arrow in FIG. 1, when the magnet 11 passes the relay 12, the latter is temporarily operated in response thereto, and closes. Current is transmitted through the electromagnet 18, delayed due to the provision of the capacitor 21, which sets the escapement timer 29 in a position such that the timer arm 31 is in a raised, inoperative position above the full line position as illustrated. Simultaneously, a positive voltage is placed on the near side of the electromagnet 23 by the closing of the relay 12; but as the switch 28 is open relative to the bar 27, the electromagnet 23 and thus the counter 33 are not energized.

The escapement mechanism 29 operates to rotate the arm 31 in a clockwise direction as viewed, and for a period of, for example, 6.00 seconds the arm 31 moves toward the adjacent end 34 of the switch 28. After 6.00 seconds of movement, the arm 31 engages the portion 34 such as to immediately close the switch 28 with the bar 27.

Thus, should the member have rotated again a complete rotation where the magnet 11 again passes by the relay 12 in less than 6.00 seconds, the responsive closing of the relay 12 will again not energize the electromagnet 23 due to the switch 28 and bar 27 being separated.

Continued operation of the timer mechanism 29 for another 2.57 seconds maintains the switch 28 closed against the bar 27 for that exact length of time. However, after a total of 8.57 seconds has elapsed since initiation of the mechanism 29 operation, the arm 31 passes beyond the switch 28 in a continued clockwise direction, and the disengaged switch 28 immediately assumes its normal, open condition relative to the bar 27.

Thus, it is readily seen that should the second rotation of the member 10 eifect by means of the magnet 11 a closing of the relay 12 during the range of time between 6.00 seconds and 8.57 seconds, the instant the relay 12 is closed energizes electromagnet 23 and activates the counter 33 to record the revolution of the member 10. Furthermore, should the second rotation of the member 10 effect a closing of the relay 12 at a time instant after 8.57 seconds of initiation of the escapement mechanism 29, even though the relay 12 closes, the electromagnet 23 is not activated due to the switch 28 having moved to an open position relative to the bar 27.

The second rotation of the member 10 which closed the relay 12 for the second time sets up the entire circuitry for a yes or no count of the third rotation of the member 10 due to the delayed resetting of the escapement mechanism 29 by operation of the electromagnet 18. It should be noted herein that the delay in resetting the mechanism 29 is for the purpose of allowing the counter 33 to be activated prior to the mechanism 29 being reset, as the reset operation effects an immediate withdrawal of the switch 28 from engagement with the bar 27.

Referring now to the FIG. 2 embodiment, a rotating member is indicated at 40 as the member the correct range revolutions of which are desired to be recorded. A north-south pole magnet 41 is fastened to the member 40, and is operable to close each of a pair of reed-type relays 42 and 43. These relays are connected, respectively, by a pair of lines 44 and 46 to a source of negative DC. voltage 47.

Relay 43 is connected through the line 48 and resistance 49 to a pair of electromagnetic relays indicated generally at 51 and 52, and which relay are isolated by a diode 53 for a purpose hereinafter described. On the side of the pair of relays 51 and 52 opposite the resistance 49, is connected a source of positive DC. voltage at 50. By means of a capacitor 54 and potentiometer 56 connected in parallel with the electromagnet 57, the latter is energized for a time period of 3.0 seconds. This time period is adjustable by means of the variable potentiometer 56. The right hand electromagnet relay 52 in FIG. 2 is energized for a time period of 4.3 seconds due to the setting of the variable potentiometer 58 thereof in parallel with a capacitor 59 and electromagnet 61.

Electromagnet 57 is operable to actuate a switch assembly indicated generally at 62, and electromagnet 61 is operable to activate a like switch assembly indicated generally at 63. The left switch assembly 62 comprises a pair of switches indicated generally at 64 and 66, the conditions of which are determined by the position of an arm 67, the arm 67 in turn being responsive to energization of the electromagnet 57. As indicated, in the normal position of the arm 67 when the electromagnet 57 is not energized, switch 64 is normally closed, and switch 66 is normally open. Upon energization, however, of the electromagnet 57, the arm 67 is moved to the right as illustrated, whereupon switch 64 is open and switch 66 is closed.

Switch assembly 63 is identical to switch assembly 62 and includes a pair of switches 68 and 69, the conditions of which are determined by a switch arm 71, the latter being determined by the condition of electromagnet 61. Should 61 be de-energized, the switch arm 71 is in the position illustrated, with switch 68 being normally closed, and switch 69 being normally open. In response to energization of electromagnet 61, the position of arm 71 is moved to the right as illustrated, with switch 68 then being open and switch 69 becoming closed.

Switches 64 and 66 have a common bar 72 which is connected by line 73 to the positive voltage source 50 and to the relays 51 and 52. The left bar 74 of switch assembly 62 is connected by line 76 to the common bar 77 of the switch assembly 63. The right bar 78 of the switch assembly 62 is connected by lead 79 through a normally off lamp 81 to the reed relay 42.

The left bar 82 of the switch assembly 63 is connected by line 83 through a normally oil? lamp 84 and line 86 to the side of reed relay 42 comparable with the lamp 81, and which side is opposite the negative voltage side thereof. The right bar 87 of switch assembly 63 is connected through line 88 to an electromagnet 89, in parallel with an NE-2 lamp 91, and through line 92 to the near side of the relay 42.

Full operation of the FIG. 2 embodiment is as follows. Upon rotation of the member 40 and its magnet 41 past the relay 43, a closing of this relay resulting from the proximity of the magnet 41 energizes both electromagnet relays 51 and 52, additionally charging both capacitors 54 and 59. By virtue of the diode 53, the left relay 51 is energized for a time period of 3.0 seconds, the capacitor 54 bleeding off through its own relay.

Furthermore, the relay 52 is energized for a period of 4.3 seconds, its capacitor 59 also bleeding ofr" through its own relay 52. Energization of the left relay 51 results in the switch arm 67 moving to the right, opening switch 64 and closing switch 66. The switch arm 71 is also moved to the right due to the energization of the electromagnet 61, opening the switch 68 and closing switch 69. Thus, under the circumstances of the timing sequence, de-energization of relay 51 will reset switch 62 in a time period of 3.0 seconds, whereas de-energization of relay 52 will result in switch 63 returning to its normal condition after an additional 1.3 seconds beyond the 3.0 seconds of switch 62, or a total of 4.3 seconds after closing of the relay 43.

Should the magnet 41 reach the relay 42, the rotating member 40 thus completing one-half a complete revolution, prior in time to 3.0 seconds after closing relay 43, the following will occur. Current from point 50 will flow through switch 66, line 79, and lamp 81, and then on through the temporarily closed relay 42 to the voltage source 47. Lamp 81 will thus be lighted indicating a too fast revolution of the member 40. It should be noted herein, that as compared to the embodiment of FIG. 1, the timing sequence here is based upon one-half revolution of the rotating member 40.

On the other hand, should the relay 42 be energized by the magnet 41 at a period of time greater than an elapsed 4.3 seconds, the following will occur. Current from the point 50 will pass through the now closed switch 64, line 76, the now closed switch 68, line 83, lamp 84, line 86, and through the closed relay 42 to point 47. Thus, to slow lamp 84 will be lighted indicating that the revolution of the member 40 is too slow. In neither the too fast nor the too slow cases, a counter mechanism indicated at 93 has been energized.

Should, however, the relay 42 be closed by the magnet 41 passing thereby at a time period within 3.0 seconds and 4.3 seconds after closing the relay 43, the following will occur. With the switch 62 in its full line, normal condition, and with switch 63 in its energized condition moved to the right from that illustrated in full lines, current will then pass from the point 50 throught line 73, switch 64, line 76, switch 69, line 88, through the electromagnet relay 89, and line 92, relay 42 to the source of negative DC. voltage 47. Energization of the electromagnet 89 will then result in the counter 93 recording the half revolution of the member 40 as taking place within the correct time range as set in the circuitry.

As the magnet 41 rotates from the relay 42 to the relay 43, the electromagnet counter 89 is de-energized by the reopening of the relay 42. The stored energy of the coils of the electromagnetic field is then dissipated through the NE-Z lamp 91, causing the lamp to flash, thus giving a visual indicationof a half revolution of the rotating member 40 having been completed within the desired time range. Subsequently, upon the magnet 41 reaching and energizing relay 43, the identical sequence as de scribed hereinbefore again takes place.

Although a preferred embodiment and one modification thereof have been described and disclosed hereinbefore, it is to be remembered that various other modifications and alterations can be made without departing from the true spirit and scope of the invention as defined in the appended claims.

I claim:

1. An apparatus for counting each revolution of a rotating member only when the rotation occurs within a predetermined time range, comprising in combination:

first means including a pair of arcuately spaced, normally open relays, each relay closeable temporarily by a magnetic device mounted on the member so as to pass and operate each relay for each revolution of the member;

a normally open electric circuit including said first means;

counter means in said circuit actuated only when said circuit is closed;

switch means in said circuit, placeable from an inoperative condition in a first open-switch condition, and placeable subsequently in a second closed-switch condition, said counter actuated only when said switch means is in said second condition, and placeable subsequently in said inoperative condition, said switch means including a pair of two position switches; and

timer means in said circuit and operable, in response to a first operation of said first means in response to rotation of the member, to eifect placement of said switch means in said first condition for a predetermined period of time after said first operation, and operable automatically to effect placement for an additional period of time of said switch means in said second condition, and operable automaticaly to effect placement of said switch means in its inoperative condition, said timer means including a pair of adjustable, time delay units having diiferent time settings, each unit having a relay operable to actuate one of said switches in timed sequence.

2. An apparatus as defined in claim 1, and further wherein said circuit includes an indicator energized through the one of said units having the lesser of said time settings, in response to closing of one of said relays immediately after closing of the other of said relays, wherein the time interval between said closing is less than said predetermined period of time.

3. An apparatus as defined in claim 2, and further wherein said circuit includes another indicator energized through the other of said units having the greater of said time settings, in response to closing of one relay immediately after closing of the other of said relays, where the time interval between said closings is greater than said predetermined and said additional periods of time.

References Cited UNITED STATES PATENTS 3,277,284 10/1966 Cripe 235-92 MAYNARD R. WILBUR, Primary Examiner I. M. THESZ, Assistant Examiner U.S. Cl. X.R. 235104 

